I recently bought a 2002 Mercedes E320 4MATIC Wagon with 122,000mi from a lady who had it sitting in her driveway for the past 2 years. Its fairly nice and well optioned.

She parked it there because she said "wouldn't move". After getting it towed back to my house, I put a new battery in it and it fired right up.

The transmission issue:
When the engine was cold, you could start the car, throw in in Drive, and i could get it to drive a few feet forward and back in my small driveway. But after a minute, the transmission pump would start to whine and the car wouldn't move at all. As you revved the engine, the whining got louder but the car didn't move. I checked the transmission fluid and it was a bit high. It was dark red in color and didn't smell burnt. I assumed the transmission filter was clogged, causing the transmission pump to be starved of oil, and thus the transmission wouldn't do anything. I dropped the pan, replaced the filter, put back in the same amount of fluid drained, and I was able to drive the car. This didn't last long however. After 16 miles, the pump started whining again and I was stuck on the other side of town. After getting towed back home, I dropped the pan again, removed the filter, and cut it open. It was filled with what looks to me like dirt. The fluid looked good, red in color and no odd smells or metal in it. Now I know its not dirt, maybe clutch material? The car drove beautifully for those 16 miles, and it shifted without issue, although I do believe these transmissions can adapt to worn clutches. Anyways, I put a new filter and fluid in, drove the car, and the transmission filter clogged after 14mi of driving. Luckily I was close to home when i heard the pump start to whine so I coasted back into my driveway, yay no tow needed! Lol. I popped a new filter and fluid in. This time the car made it 73 miles, better, but still not good at all. This time however, I limited the car to only go as high as 4th gear, so overdrive wouldn't engage. At about the 68 mile mark i put it back into Drive and drove around 55mph in 5th gear, shortly after is when the pump started whining. I have no clue if this could be part of the issue or if its just a coincidence, but i thought I'd add that. I assume anyone would say I need a new transmission, or to get it rebuilt at the very least. Could this possibly be something else, perhaps the torque convertor? I also want to add that this "dirt looking stuff" in the filter was non-magnetic. I'll attach a pic below.

 

Okay so the stuff I'm seeing in there is clutch material? Do you know why the transmission would fail like this at just 120k miles?

 

doesn't have to smell burnt to be done

particles sit in suspension in the fluid, fluids dirty, but it hasn't oxidized yet. Fluid begins to oxidize, aerate, then burn as it ages, but the clutch material in suspension is just normal operation wear and tear. The more of that stuff you keep in suspension the less efficient the fluid is. I would do a couple transmission services within close intervals to do as much as you can. Most people think the friction discs are the wear item, but it's usually the fluid. A set of friction discs and steels can last virtually forever if you take care of the fluid supply. The fluid is responsible for the hydraulic functions that make the clutches meet, but also they lubricate the clutches/metal bushes in the valve block.

 

We had a similar issue (clutch material but no metal in the trans filter). Transmission pump was clogging after running the car for bit. Left us stranded a few times. After the car sits for a while, we could drive again until it clogged and we went into limp home. My mechanic had seen this in another 722.6 and suggested we trying more frequent filter changes for a bit. Ended up changing the filter every 2500-3000 miles for a couple of changes, then shifted to a 10K mile change and then 20K mile change.Shifts smooth. We have driven on multiple trips over 300 miles and had no issues.
182K / Issue started in late 2016
185K filter change
188K filter change
198K filter change
205K fluid/filter change
224K filter change
now at 234K miles

 

That gives me some hope, thank you! Unfortunately though I found a lot of fine gold colored shavings in the oil after I drained it today. The 73 mile oil filter was clogged again from clutch material causing the pump to run dry I believe. I was right up the road when I heard it start whining last time, I made one left hand turn onto my street while the pump was whining and that's the only time I hit the gas, I was able to coast for the rest. I just put a new filter and fluid in and I'll reply back if or when it clogs again 😓

Does anyone know where these gold shavings would come from? I will be starting my search for a used tranny but for now I want to try my best to save this one

 

Does anyone know if this could be from a failing torque converter? The filter clogged after driving another 70 miles. I will be pulling the transmission and tearing it apart this week. I’d hate to rebuild it and have it clog again due to it being something else wrong.

 

I am no MB expert, but have rebuild several older GM transmission. IF and when you decided to open your trans, make sure you have the 1.) Trans manual specific to your trans. 2.) Special tool(s) you need for that trans. 3.) Lots of trays to put your now disassembled trans part. many many parts within the trans look a like, specially those o-rings/gaskets. 4.) Take a lots of pictures. This is easier said than done. Remember, your hands, with or without gloves will be covered with some kind of fluid. 5.) did I mention manual for the trans?

Once you open up the trans, you will then will see what's wrong with your trans. I really doubt it's your converter. However, converter will hold majority of the trans fluid, so if you have those clutch material, most will be trapped inside the torque converter, so you either need new converter or have them flush out at the trans shop. Or better yet, have them cut it out and clean it. Not sure about MB, but Chevy happens to be cheaper with newer unit unless you have a custom converter that was built for your engine combo/stall speed.

Lastly, trans rebuild is lot more than just taking off the valve body and clean it. With that much clutch lining particle suspended in the fluid, probably better to open up the trans and do the full rebuild. You gonna have it out anyway. Do it yourself or taking it to the trans shop, it's way easier and cheaper. Just make sure you take it to reputable shop. Don't, again, don't even think about taking it to nationwide trans shop. If you decided to tackle this yourself, make sure you get a quality parts, such as clutch lining. I'm pretty sure you don't want to drop or rebuild your trans again after this.

Above is my experience from GM and Ford trans. TH-350, TH-400 and 200-4R. Not rebuild, but did some work on Ford AOD and 5R55S. Nowadays, I have someone else drop the trans for me, and I'll do the rebuild. Getting too old for dropping trans.

 

I pulled the transmission out of the car a couple days ago and just pulled the transmission apart today. Take a look below at the B2 clutch housing clutch pack. One of the clutch discs appears to have completely failed and delaminated.

What should my next move be? Complete rebuild? Could something else be the issue and causing this clutch to fail?

 

thats going to be a good start but it's going to be more than that since the transmissions actually still work like that. I think the grit also loosened some of the tolerances. So at the minimum I'd do the o-rings frictions and steels just to get it back together, but I'd replace all the bushings at minimum too. As far as transmissions go they're not that complicated compared to the later 722.9 so if you have experience with 4L60's like I do it sort of makes sense.

https://transend.us/products/transmi...ls-kits/78004c

That'll cover the frictions and steels, then you should always replace the bushings for the pump and shafts. I also highly recommend upgrading the shift sleeves in the valve body while you're in there.

https://www.sonnax.com/units/211-722-6

Even with all this I typically don't like re-using a pump without checking to see how much trash has flown through it. Basically it's a game of, does my transmission still have friction, and does it still have line pressure after a bunch of grit has blasted through it

 

Fortunately the transmission did still work. It shifted beautifully through all the gears and I had 0 issues while driving. The issues started when the clutch material found its way to the filter and starved the transmission of oil. If I replaced the filter I could drive it until the clutch material clogged it again. I've heard this delamination can be caused by water getting in the transmission which has me worried for all the other friction disks. The other frictions look fine but I suppose looks can be deceiving. I had no signs of water or coolant in the transmission, at least not anything that's visible. I have yet to test the fluid.

 

Again, I am no MB mechanic or specialist, but on the trans I've worked on, deteriorated friction/steel plates are from trans running too hot or overheated trans. Also, I'm not sure which came first, failed pump or friction plate going bad, but usually, when trans is clogged with that much materials and starved, you need new trans pump, or at least a rebuild a pump. And don't forget to flush all the lines and trans fluid cooler if equipped.

Also, you question of should you do a complete/full rebuild? I say yeah. What are the chance of you removing the trans, AGAIN. Yes, other friction plates in the picture doesn't look bad at all, but you have the trans out. You can also check other part of the trans since trans was starving for fluid. I wouldn't be surprise to find other parts, such as shaft and drums with some kind of burnt mark or scratches. But then again, we're talking about MB, not Chevy or Ford so I could be wrong. But I would go as far as disassembling them and check for burn marks and scratches. I'm not too worry about the hard parts, but case is made out of Aluminum. If there's a burnt mark or scratches on the hard parts, check the case. Of course, even the hard parts, if they are scratched deeply or burnt badly, you may need to replace them as well.

Lastly, once again, my experience are from Chevy and Ford trans, so it could be completely different on MB we drive.